代码示例:(标识:eg_js_date_new_day)
<!DOCTYPE html>
<html>
<body>

<h2>JavaScript new Date()</h2>

<p>使用 new Date(<i>milliseconds</i>),创建一个零时(January 1, 1970, 00:00:00 Universal Time)加毫秒的新日期对象::</p>

<p id="demo"></p>

<script>
var d = new Date(86400000);
document.getElementById("demo").innerHTML = d;
</script>

<p>一天(24小时)是 86,400,000 毫秒。</p>

</body>
</html>
运行结果: